Instructables
Written for beginners by a beginner. This project is my first project using LEDs, and I have documented it to present it to the world. I mounted two green LEDs in a sign that I could hang in my bathroom to solve certain...ahem..."problems."
 
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Step 1: Materials

Picture of Materials
This is the list of parts I used in my project. All electronic parts were bought from Radioshack. If you can stand to wait, order some parts online. Radioshack has an absurd markup price. I went there because I'm an impatient teenager, and I wanted to do the project NOW. I am using a potentiometer because i wanted to be able to dim the LED, and a switch to turn it on and off.


-A two pack of green LEDs (part number 276-304)
-a SPST (single pole, single throw) toggle switch (part number 275-612)
-a 10 ohm resistor. I just had this lying around.
-3 AA batteries
-a 5K audiotaper Potentiometer (part number 271-1720)
-random pieces of wire that I had lying around.
-an "aquired" sign.
-a soldering iron

Step 3: Making the battery pack

I forgot to buy a battery holder, so insead of having to drive back to Radioshack to buy one, I just soldered three batteries together and duct taped them together. If you feel like it though, go ahead and buy a holder, and skip this step.

This is simple, just solder the "+" end of the battery to the "-" end of the other. It should be labeled on the battery which end is which, but if not, the flat end is the negative side, and the side with the little bump is the positive end.
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Where did you get the knob? RadioShack?
sci4me5 years ago
Why do you have a potentiometer?
potentiometer is used to increase or decrease the light of LED
o. :D
agis684 years ago
Guys take it easy, It's true, in Technical University they told us that is dangerous to solder on batteries. But I did it so many times I forgot the number. Iam 42 and I am doing this for 22 years. Nothing happened ever to me or any other technician I know. The secret it's one....Yes you can solder on batteries, but very quick and shortly.
Ive done it too but anyone is skeptical they can just buy a batery holder or tear one out of a broken toy.
zeero3607 years ago
mst u guys r lucky i cant buy LEDs
Why Not???
i checked all the hobbie shops and nothin i dont no where else to check u got any ideas
Might find some in the dump or on junk by the wayside if all else fails.
Okay,
If you have a Paypal, you can order of the internet from one of the two stores:

http://www.radioshack.com/search/index.jsp?kwCatId=&kw=led&origkw=LED%20&sr=1

http://www.sparkfun.com/commerce/categories.php?cPath=51_89

If you have a Radio Shack near you, you should go there, here is a store Locater:

http://www.radioshack.com/storeLocator3/index.jsp?clickid=rsk_header_storeLocator

I Hope I helped.

~Alex
BillVT6 years ago
Please note: soldering to a battery is an excellent way to heat up and potentially cause an explosion. It is best to use electrical tape or some other adhesive rather than solder directly to a battery terminal. Be Safe rather than Sorry and covered in an acidic mess!
w00t acidic messes :D ugh not fun to get Battery acid in your eyes o.o
red-king BillVT6 years ago
yeahhhh... its not really a good idea to solder to a bettery...
PyroMonger5 years ago
why would you need a pot for this circuit? I don't see a need for dimming the leds
Code for falstad circuit simulator (http://www.falstad.com/circuit/):
$ 1 5.0E-6 382.76258214399064 50 5.0 50
v 336 272 336 256 0 0 40.0 1.5 0.0 0.0 0.5
v 336 256 336 240 0 0 40.0 1.5 0.0 0.0 0.5
v 336 240 336 224 0 0 40.0 1.5 0.0 0.0 0.5
s 336 224 336 176 0 0 false
174 368 160 304 160 0 5000.0 0.9950000000000001 Pot. Position
r 304 160 240 160 0 10.0
162 240 160 240 224 1 2.1024259 0.0 1.0 0.0
162 240 224 240 288 1 2.1024259 0.0 1.0 0.0
w 240 288 336 288 0
w 336 288 336 272 0
o 5 64 0 35 0.3125 0.025 0 -1
sasuto5 years ago
Yeah REALLY BAD IDEA to solder battery or any other kind of engery sources.
ilovelorie6 years ago
Thanks for making this tutorial. I didn't know where to look to start learning this and everything seems so advanced. I plan on putting some LEDs on one of my art pieces and i needed it to blink so I will go slow and keep up with your lessons. :) thanks much
either i'm now thinkin today or i'm right because i'm pretty sure there is no such thing and no reason as a 10 ohm resistor
flare7656 years ago
nice im gonna try something like that
Patented6 years ago
is the potentiometer is only for the look?I don't understand
Close, the knob is for looks, the pentiometer is a variable resistor that makes the LEDs brighter or dimmer.
Nice, thank you!
You're welcome.
Flushing? *Pshaw*
zachninme8 years ago
Why not use a pizeo transducer to pick up on the loud flush, and then shut off after that? Simple flip-flop chip should do the job!
nice idea! I think it would be mroe affective to use a switch inside the toilet on the flushing handle tho (be sure not to get it wet)
stringteary7 years ago
MattDurr7 years ago
sorry to tell you this but the link that you posted has changed and that page does not exist anymore so you should think about changing it
zhdai8 years ago
Very nice site!
http://www.eefl.cn
http://www.cn-ovl.com
http://www.slim-lightbox.com
http://www.rondeflower.com
OVL-Good ccfl,eefl, ccfl ring, ccfl PC kits, sound controller, Lightbox, El-panel, Backlight materials inverter supplier
richjd8 years ago
I like your LED project. May I suggest that you add aschematic diagram. As a beginner in electronics you could learn much by drawing one. Great stuff...... richjd
eight8 years ago
Personally, I think a 12v inverter (as used in a CCFL) connected to the metal urinal and step would negate the need for a LED. The audible signal could be heard for many kilometers :P 'Scuze my dry sense of humour. It's an Aussie thing ;) Great post ! - eight
jgrimes2278 years ago
Simple! But thats because you did an awesome job on the instructions. GREAT JOB. I wish only a few of the adults on the Corvette Site I belong to could explain things as clearly and completely as you have done. I really like the idea one guy had of adding a motion detector to trigger the Flush lights - now how about one for put the g---damned seat up!! and Wash your hands. The only problem I see is naming your yacht after you have made a fortune selling these things restaurants and other public bathrooms.
sharpdust8 years ago
If the wires from the switch (each post I mean) are touching eachother will the switch become useless? If so, is it possible to completely just get rid of the switch and just use the potentiometer? I would try it myself, but I just completed the project and I basically have a crap load of electrical tape everywhere (I didn't try soldering because I suck at it) and I want to make sure it would work that way if I did it.
JethroWho158 years ago
how come when figuring out which resistor you need and you used the led caculator you said you nedded a volate drop to 2.1 I though you only neede a voltage drop to 4.2 because there are 2 led's
Sweet sauce! I just finished making mine. This is my first soldering project. Thanks much for the directions and idea!
bustersdad8 years ago
Thanks for the info on the calculator. I have wanted to "play" with LEDs for a while but that math piece was getting in the way. With this information in hand I think I can do it. Thanks again!
cyenobite8 years ago
great instructable and for a beginner like me I think I can follow this one!
AND you made the MAKE blog!
http://www.makezine.com/blog/archive/2006/04/led_beginner_project.html
Thanks for posting
Cyen
http://cyenobite.blogspot.com
Willd (author) 8 years ago
thanks for the correction Invisible!
I'm a reeeeeel beginner at this electronics stuff. so a simple project like this helps me learn a lot. Thanx a bunch.
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